>>>>> "ralf" == Ralf Baechle <ralf@linux-mips.org> writes:
ralf> On Thu, Apr 03, 2003 at 04:11:02PM +0200, Maciej W. Rozycki wrote:
>> Hmm, erratum #2 is about status output pins. I suppose you mean erratum
>> #5. But then it applies to V3.0, too.
>>
>> Then the bit is r/w, so how about toggling it instead of panicking?
>> With an informational message like:
>>
>> printk(KERN_ERR "Firmware bug: 32-byte I-cache line size unsupported for
>> the R4000...\n");
>> printk(KERN_ERR "... fixing up to 16-byte size.\n");
>>
>> Of course that probably requires a temporary cache inhibition and
>> invalidation.
ralf> I know of one machine where changing the size of the cacheline is supposed
ralf> not to work, that's the MIPS Magnum 4000 and it's close relatives.
ralf> Anyway, I put the check there for the unlikely case there are broken
ralf> systems out there. In practice I assume vendors were aware of this
ralf> problem and the check is purely theoretical and for paranoid correctness's
ralf> sake.
ralf> It seems like changing the configuration to larger cache lines where
ralf> possible should improve performance somewhat. If all the cache code is
ralf> working truly correct we also should no longer see VCE exceptions on
ralf> R4000SC processors - the reason why Indys are still a valuable test tool.
I still got lot of them :(
VCED exceptions : 1544376
VCEI exceptions : 92380
That machine was booted yesterday night. I haven't login on it,
i.e. only normal daemons for a nfsrooted machine running.
Later, Juan.
--
In theory, practice and theory are the same, but in practice they
are different -- Larry McVoy